“This is the first time something like this has happened in this shop. There have been break-ins at Penicuik recently but nothing like this. We have CCTV, but I think we will be increasing our security here.”

The suspect is described as white, 20 to 30, 5ft 3in to 5ft 8in, medium build, with dark shoulder-length hair and stubble. He had a Scottish accent and wore a dark hooded top.

A police spokesman said: “Anyone who was in the area of John Street or Carnethy Road around the time of the robbery, who noticed anyone acting suspiciously in the area, should contact police.

“Likewise anyone who recognises the description of the suspect, or who has any other information that can assist our inquiries, should get in touch.”